Vibrational Raman spectroscopic transitions are used to probe the dynamical processes involved in lipid-lipid interactions in model membrane bilayer assemblies. Specifically, spectral changes are used to monitor integral and peripheral membrane components, to determine intrachain and lateral intermolecular disordering effects within the phospholipid matrix, to estimate the size of the cooperative unit involved in the gel-liquid crystalline phase transition and to describe the formation of membrane complexes. BIBLIOGRAPHIC REFERENCES: Bunow, M.R. and Levin, I.W.:Vibrational Raman spectra of lipid systems containing amphotericin B. Biochem. Biophys. Acta 464: 202-216, 1977. Yellin, N. and Levin, I.W.: Hydrocarbon chain trans-gauche isomerization in phospholipid bilayer gel assemblies. Biochemistry 16: 642-647, 1977.